In many cases there is a need to provide an ear cup of a hearing protector with one or more electrical components which may comprise for example a microphone for receiving voice from outside of the ear cup and for converting the voice into an audio electrical signal. The ear cup may further comprise a signal processing system for processing the audio electrical signal. The signal processing system may comprise for example a filter for filtering the audio electrical signal and an earphone for procuring voice corresponding to the filtered audio electrical signal. The filter can be adapted to attenuate impulse noise and/or to attenuate signal components which do not belong to a desired frequency band, e.g. to the frequency band of speech.
Design of the ear cups of a hearing protector is critical for outside noise attenuation. Any holes or openings on the outer casing of an ear cup cause noise to leak inside and thus the holes or openings deteriorate significantly the noise reduction properties of the ear cup. In addition, any hard material that occupies a portion of the internal volume of the ear cup deteriorates also the noise attenuation properties because the room for soft noise-damping material is diminished.
A microphone and user interface devices, such as e.g. push buttons, are typically mounted mainly inside an ear cup and have large openings in the outer casing of the ear cup. For example, a classical cylindrical electret condenser microphone is typically mounted to a wide opening of the outer casing with the aid of a rubber mounting and sealing element. Therefore, the traditional way to provide an ear cup of a hearing protector with a microphone and with user interface devices deteriorates the noise reduction properties.